Method of forming a sheet metal cup without a mandrel

Abstract

The invention comprises a method of forming a sheet metal cup without using a mandrel. A cup shaped blank is first produced having a relief on a rim or outer circumference. The blank is clamped in the spinning machine. The relief controls and facilitates the bending process, creating a uniform curve at a predetermined bending point. During the rolling process, a forming roller is engaged with rim, and is moved progressively parallel with an axis of rotation. As the forming roller moves, the rim is progressively bent from an orientation normal to an axis of rotation to a position parallel to the axis of rotation. The fully formed rim can then be punched to accommodate a bearing or shaft. This allows a small radius pulley to be formed without use of a mandrel.

Dependencies are inferred from the claim text.